When we see records being broken and unprecedented events such as this, the onus is on those who deny any connection to climate change to prove their case. Global warming has fundamentally altered the background conditions that give rise to all weather. In the strictest sense, all weather is now connected to climate change. Kevin Trenberth

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Debbie Barker is the international programs director at the Center for Food Safety. Michael Pollan is the John S. and James L. Knight professor of journalism at the University of California at Berkeley.

When Will Allen is asked to name the most beautiful part of his Vermont farm, he doesn’t talk about the verdant, rolling hills or easy access to the Connecticut River. Though the space is a picturesque postcard of the agrarian idyll, Allen points down, to the dirt. “This precious resource not only grows food,” he says, “but is one of the best methods we have for sequestering carbon.”

We think of climate change as a consequence of burning fossil fuels. But a third of the carbon in the atmosphere today used to be in the soil, and modern farming is largely to blame. Practices such as the overuse of chemicals, excessive tilling and the use of heavy machinery disturb the soil’s organic matter, exposing carbon molecules to the air, where they combine with oxygen to create carbon dioxide. Put another way: Human activity has turned the living and fertile carbon system in our dirt into a toxic atmospheric gas.

It’s possible to halt and even reverse this process through better agricultural policies and practices. Unfortunately, the world leaders who gathered in Paris this past week have paid little attention to the critical links between climate change and agriculture. That’s a huge mistake and a missed opportunity. Our unsustainable farming methods are a central contributor to greenhouse gas emissions. Climate change, quite simply, cannot be halted without fixing agriculture.

The industrialization of farming has allowed farmers to grow more crops more quickly. But modern techniques have also wreaked havoc on the earth, water and atmosphere. Intense plowing, for example, has introduced more oxygen into the soil, boosting the microbes that convert organic matter into carbon dioxide. The quest to wring every last dollar out of fields has put pressure on farmers to rely on chemical fertilizers. This often leaves fields more bare between growing seasons, allowing carbon to escape into the air. Scientists estimate that cultivated soil has lost 50-70%of its carbon, speeding up climate change.

That loss has significantly degraded soil health, reducing our ability to grow food. Median crop yields are likely to decline by about 2% per decade through 2100, according to the U.N. Intergovernmental Panel on Climate Change. At the same time, the world’s population is projected to jump from 7 billion to 9 billion by 2050.

Water availability is also at risk. Currently, 1.6 billion people live in regions facing severe water scarcity; that number is expected to rise to 2.8 billion by 2025. Agriculture accounts for a whopping 70% of all water consumption. That’s in large part because degraded soil doesn’t absorb water efficiently. Instead, water sits on top of the ground and runs off (along with farm chemicals) into nearby waterways, creating toxic nitrogen “dead zones.”

Remarkably, though, restoring carbon to the soil is not nearly as complicated as rethinking our transportation systems or replacing coal with renewable energy. Innovative farmers such as Allen already know the recipe.

He and his team place “cover crops” in their fields, planting things like oats, rye and beans between rows of vegetables. This practice keeps carbon, nitrogen and other organic nutrients in the soil. “Keeping as much ground covered with plants as long as possible allows photosynthesis to draw down atmospheric carbon into soils,” Allen says. A bare field, in contrast, represents a waste of photosynthetic potential. Allen also composts, limits plowing and avoids synthetic chemicals like nitrogen fertilizers. In combination, these efforts have increased soil organic matter by 3 to 4 percent in just three years. Allen also sells some of his cover crops, adding farm income.

Allen’s results are not unusual. Studies have shown that cover cropping, crop rotation and no-till farming could restore global soil health while significantly decreasing farms’ carbon footprint. Some scientists project that 75 to 100 parts per million of CO2 could be drawn out of the atmosphere over the next century if existing farms, pastures and forestry systems were managed to maximize carbon sequestration. That’s significant when you consider that CO2 levels passed 400 ppm this spring. Scientists agree that the safe level of carbon dioxide in the atmosphere is 350 ppm.

Regenerative farming would also increase the fertility of the land, making it more productive and better able to absorb and hold water, a critical function especially in times of climate-related floods and droughts. Carbon-rich fields require less synthetic nitrogen fertilizer and generate more productive crops, cutting farmer expenses.

So why aren’t we instituting policies to encourage this kind of “carbon farming”? For one thing, the science is new and not yet widely disseminated. Additionally, most of the incentives built into America’s agricultural policies are based on maximizing yield, often at the expense of soil health.

Current federal policy, for example, limits the growing season for cover crops on the theory that they waste farmers’ time and resources on products that can’t be sold. Thus, farmers are denied full crop insurance, price supports and subsidies if they grow cover crops beyond a specified period of time. But viewing cover crops as a benefit instead of an impediment to cash crops would be the kind of climate-smart policy we need. And, as farmers such as Allen have learned, some cover crops can also be commercialized.

Giving farmers incentives to switch from synthetic nitrogen fertilizers to organic fertilizers could also lead to healthier soil. Scientists at the University of California at Berkeley working with Marin County ranchers have found that applying a single layer of compost, less than an inch thick, to rangelands stimulates a burst of microbial and plant growth that sequesters dramatic amounts of carbon in the soil — more than 1.5 tons per acre. And research has shown that this happens not just once, but year after year. This is a win-win strategy, both for the climate and the food system, since the additional carbon in the soil means more grass for cattle and more profit for ranchers. If the practice were replicated on half the rangeland area of California, it would sequester enough carbon to offset 42 million metric tons of CO2 emissions.

The possibilities are endless. What if our farmers received federal subsidies not just for bushels per acre, but for carbon sequestered or acres of cover crops planted? Many such changes could be made tomorrow at the agency level; they would not require congressional action. Incentives for carbon farming could also bridge the political chasm between ranchers, farmers and environmentalists. Even those farmers and ranchers who don’t believe in climate change desire healthy soil, high productivity and lush grasslands. There is a rich opportunity here to completely realign the politics of agricultural and environmental policy.

America is not there quite yet, but other countries are pointing the way. This year, the French government launched the 4 Per 1000 initiative, the first international effort to restore carbon to the soil. Under the proposal, nations would commit to increasing the carbon in their cultivated lands by 0.4% per year. The French calculate that this would halt the annual increase in carbon dioxide emissions. Some emerging soil science estimates that we could store 50-75% of current global carbon emissions in the soil.

In the United States, when the Dust Bowl crisis of the 1930s literally blew soil across the country, our government responded by implementing agriculture policies to ameliorate the problem. With the stakes even higher today, our politicians can once again enact policies to reward practices that rebuild soil carbon.

Abstract

Glyphosate is the most widely used herbicide in the world, but its effects on non-target organisms, such as arbuscular mycorrhizal fungi (AMF), are unclear. No studies have been found that made reference to effects of glyphosate on AMF spore viability despite its importance as a source of propagules for the perpetuation and spread of AMF in the system. The objective of this study was to evaluate the effect of glyphosate application on AMF spore viability, and their ability to colonize roots. Soil samples were collected from a grassland area located in the Flooding Pampa region (Argentina). We evaluated three herbicide rates: 0, 0.26 and 1× recommended field rate, 10 and 30 days after application. Part of the soil from each tray was used to estimate the spore viability, and the remainder was used as substrate for growing Lolium multiflorum Lam. One month after sowing, total root colonization and percentage of arbuscules and vesicles were determined. The spore viability in herbicide untreated soils was between 5.8- and 7.7-fold higher than in treated soils. This reduction was detected even when the lower rate was applied. Root colonization was significantly lower in plants grown in glyphosate treated soil than in untreated ones. A decrease in arbuscular colonization (but not in vesicles) was found in plants grown in soils treated with the highest herbicide rate. That would indicate that symbiosis functionality was affected, given that arbuscules are the main site for host–fungus nutrient exchange. The results indicate that soil residence time of glyphosate and/or its degradation products was enough to reduce AMF spore viability and their ability to colonize roots. This decrease in propagules viability may affect plant diversity, taking into account the different degrees of mycorrhizal dependency between plant species that may coexist in grassland communities.

NASA Satellite Images Uncover Underground Forest FungiA NASA-led team of scientists has developed the first-ever method for detecting the presence of different types of underground forest fungi from space, information that may help researchers predict how climate change will alter forest habitats.Hidden beneath every forest is a network of fungi living in mutually beneficial relationships with the trees. Called mycorrhizal fungi, these organisms spread underground for miles, scavenging for nutrients that they trade with trees for sugars the trees make during photosynthesis. "Nearly all tree species associate with only one of two types of mycorrhizal fungi," explained coauthor Richard Phillips of Indiana University, Bloomington.Because the two types of fungi are expected to respond differently to a changing climate, knowing where each type predominates may help scientists predict where forests will thrive in the future and where they will falter.Creating maps of forests and their fungi has traditionally relied on various methods of counting individual tree species, an approach that cannot be done at large scales. In a new study published in the journal Global Change Biology, a team led by Joshua Fisher of NASA's Jet Propulsion Laboratory, Pasadena, California, and UCLA found a way to detect this hidden network using satellite images.Every tree species has its own spectral signature -- it absorbs or reflects light in a specific pattern across all the wavelengths in the spectrum of light. Using satellite images of forest canopies, Fisher's group probed whether they could identify any patterns in the spectral signatures of tree species associated with one type of fungus that did not appear in species associated with the other type.Fisher explained, "Individual tree species have unique spectral fingerprints, but we thought the underlying fungi could be controlling them as groups."The team studied images of four U.S. forest research plots that are part of the Smithsonian Institution's Forest Global Earth Observatory. In these forests, which include 130,000 trees across 77 species, the tree species associated with each type of fungus had already been mapped from the ground. The researchers analyzed images of the forest canopies taken by the NASA/U.S. Geological Survey Landsat-5 satellite from 2008 to 2011 in many different ways, searching for similarities that lined up with areas of fungus dominance. They found what they were looking for when they examined various milestones throughout the growing season, such as when the trees leafed out in spring and when they reached peak greenness. There were significant differences in the timing of these milestones between regions dominated by the two types of fungi.Having identified the timing sequences related to each type of fungus, the researchers developed and tested a statistical model to predict the areas of fungus domination in any particular Landsat image from canopy changes alone. They found they could predict the fungus association correctly in 77% of the images. They went on to produce landscape-wide maps of fungi associations, uncovering intriguing patterns in forests that will be studied in greater depth in the future.Fisher said, "That these below-ground agents manifest themselves in changes in the forest canopies is significant. This allows, for the first time, some light to be shed on their hidden processes."NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing. The work was also funded by the U.S. Department of Energy and the National Science Foundation.For more information about NASA's Earth science activities, visit:

Cameron Wake, professor of climatology and glaciology at the University of New Hampshire, said Portsmouth homeowners in low-lying areas in the South End consider selling their houses now. Photo by Ioanna Raptis/Seacoastonline

PORTSMOUTH — People who live in a low-lying area of the city like the South End should consider selling their house — “and I’m not kidding,” said Cameron Wake, University of New Hampshire professor of climatology and glaciology.

If there is a big coastal storm like Hurricane Sandy, “those houses are at risk of flooding” today. And it won’t get any better in the years to come, as sea levels inevitably continue to rise.

“My recommendation is why deal with the headache? Sell now while you can still get money out of the home,” he said.

As for Hampton Beach, he said, the town’s move toward making the beach a 5-star resort area is misguided at best. “Hampton Beach is so at risk, so vulnerable, so exposed” that it makes no economic sense to continue on that path.

Wake spoke to the Herald editorial board Wednesday, in advance of his talk next week at 3S Artspace in Portsmouth. He said sea level rise from climate change is occurring now and its trajectory is inevitable. The question is how quickly will we curtail human activities that contribute to global warming?

Will carbon emissions continue unabated at current levels — in which case sea levels could rise as much as 6 feet in the next 80 years, leaving Hampton Beach, Strawbery Banke Museum, Portsmouth Middle School and South Mill Pond homes in Portsmouth under water? “I don’t mean to be hyperbolic here, but that’s the picture,” said Wake.

Or will there be a serious and immediate commitment to reducing carbon emissions by systemically investing in renewable energy sources, weaning off high carbon use, implementing energy efficiency measures and instituting a carbon tax? In the most optimistic case, then, sea levels would rise 2 feet over the next 80 years, “something we can adapt to, something we can survive.”

Wake sees reasons for optimism amid concerns that the planet could be facing “a whole suite of nasty surprises” in the future — including the possibility of more accelerated melting of the Greenland and West Antarctic ice sheets than had previously been anticipated. Former NASA scientist James Hansen in a study released this week predicted even if the Earth warms by a modest 3.5 degrees Fahrenheit by 2100 — as agreed to by the nations of the world in Paris last December — it will be too warm to stop the sheets from melting. That would cause sea levels to rise quickly and precipitously, the study argues.

“The conversation we’re not having is the conversation Jim Hansen wants us to have,” said Wake. “We had to get over the denial, and we’ve done that. Now we need to take a hard look at where we go from here.”

Wake was asked what number he would assign the world today, if zero was the worst carbon pollution possible and 10 was the perfect climate world.

“I think we’re at about a 1," he said. "The developed world needs to be carbon neutral by 2050. We need to get to 10 really quickly,” he said, and then help developing countries reach that goal in the decades to follow. “But when you look at the rate of change today, we’re headed in the right direction.”

That’s where the optimism comes in, he said. It’s become clear in recent years that a solution to global warming is becoming cost effective, he said. The cost of wind and solar has come down, for instance.

“We can see a pathway to a clean energy revolution that wasn’t there before. The tipping point is where capital, interest and technology all meet. I’m optimistic because solutions line up with profit motives,” he told the Herald last December.

He likened it to the Internet. Early on, comparatively few people used the Internet, but then it reached the same critical mass “and took off exponentially. That same exponential curve is happening now” with renewable energy.

In order for this trajectory to continue, people need to incorporate changes in their personal lives, and begin demanding their elected leaders from town hall to Congress deal with this issue. “Once politicians hear from many people, I think they will start to get much more serious.”

While there are many challenges ahead, he said, he said “it’s not too late. There is an amount of climate change we are going to have to adapt to. We have already committed to a warmer world. But if we can act now, in the next decade, and the developing world in the next two or three decades, I do think we can salvage this.”

Rep. Lamar Smith (R-TX) at a recent hearing claimed a new study published in the journal Nature Climate Change “confirms the halt in global warming.” It doesn’t. In fact, the authors of the paper write, “We do not believe that warming has ceased.”

Smith, chairman of the House Committee on Science, Space, and Technology and longtime climate change skeptic, used the Nature study as ammunition against the National Oceanic and Atmospheric Administration in an ongoing battle over the validity of a paper that NOAA researchers published in the journal Science last June.

While the Nature study, published online in late February, claims there was a “slowdown” in the rate of global warming in the early 21st century, the Science paper argues there was not. But the studies compared different time periods. Both studies agree that there was no complete halt in global warming and the long-term warming trend remains unabated.

At the March 16, 2016, House hearing, Smith also continued to criticize the Science paper. He said the paper was “prematurely published,” but the editor-in-chief of Science told us Smith’s claim is “baseless and without merit.” Smith also said that the NOAA researchers used “controversial methods” in their study, but the authors of the Nature paper cited by Smith said this wasn’t the case. In fact, they cite the Science paper as having “high scientific value.”

Overall, each study asked different scientific questions, the answers to which can both remain valid and correct, according to the Nature authors themselves.

Smith vs. NOAA

This is not the first time Smith, a Republican from Texas, has made false statements about climate science and the so-called “Karl study,” named after Thomas R. Karl, director of NOAA’s National Centers for Environmental Information and the Science paper’s lead author.

As we’ve written before, Smith claimed in October 2015 that “climate data has clearly showed no warming for the past two decades” and that NOAA scientists “altered the data” to get the results they presented in the Science study.

Motivated to quell what he considers the NOAA and Obama administration’s “extreme climate change agenda,” Smith used the House science committee’s subpoena power on Oct. 13, 2015, to obtain internal communications at NOAA regarding the Karl study. NOAA has provided the committee with some documents and emails, though Smith continues to request more information.

In the battle’s latest episode, NOAA Administrator Kathryn Sullivan testified before the House science committee on March 16 on NOAA’s 2017 budget. Again, Smith brought up the Karl study, claiming it was “prematurely published” and used “controversial new methods,” among other things.

During the hearing, Sullivan countered by stating that the final timing of any publication is “at the discretion of the publication itself.” She also said Science “scrubbed this paper with extra diligence” due to the “interest in this matter.”

According to Marcia McNutt, editor-in-chief at Science, Smith is wrong and Sullivan is right. In fact, McNutt told us by email, “Any suggestion that the review of this paper was ‘rushed’ is baseless and without merit.”

McNutt added that “knowing that this report’s results disputed the existence of a 21st century global warming slowdown described in previous studies, Science took extra care to assure even more rigorous review and evaluation than normal.”

When asked to provide evidence that NOAA had prematurely published the Karl study, a committee aide for Smith pointed us to a Nov. 23, 2015, Washington Post article. In that article, Thomas Peterson, an author of the Science study and retired NOAA climate scientist, describes “internal tensions” between NOAA scientists and engineers over delays related to the programs used to process the climate data. But in the same piece, Peterson is quoted as stating that the research was not rushed. “Indeed just the opposite is true,” he told the Post.

Smith made a few new claims during the March 16 budget hearing as well. He said, “A new peer-reviewed study, published in the journal Nature, confirms the halt in global warming. According to one of the study’s lead authors, it ‘essentially refutes’ NOAA’s study.” Smith also repeatedly asked Sullivan to side with either the Science or the Nature study’s findings because he claimed both can’t be “correct” or “valid.”

First off, the two papers’ disagreement was on whether the rate of warming has slowed in the first 15 years of the 21st century, not whether warming has halted, as Smith claimed.

Second, John Fyfe, lead author of the Nature paper, told us in an email that Smith took his comment during an interview with the website Climate Central out of context. “It would be incorrect to interpret [the ‘essentially refutes’] quote as indicating that Fyfe et al. refuted the Karl et al. study in its entirety.” He said, “As we said in our Commentary we view the Karl et al. study as being of ‘high scientific value.’ ”

Third, according to McNutt and the Nature authors, both papers could, in fact, remain valid and correct. For example, Gerald Meehl, an author on the Nature paper and climate scientist at the National Center for Atmospheric Research, pointed us to a segment of an article with Environment & Energy Publishing, which states “both comparisons are valid … and provide answers to different questions.”

In the following section we’ll explain the similarities and differences between the two papers’ methods and results and why both can remain valid.

Science vs. Nature

Both the Science and the Nature papers begin by mentioning the Intergovernmental Panel on Climate Change’s description of a surface warming slowdown between 1998 and 2012 in its Fifth Assessment Report. Both papers also note that researchers use “hiatus” to describe this slowdown in the scientific literature — a point Smith’s committee aide made to us. But technically the rate of global warming never completely halted during this period, as both papers state.

For this reason, the authors of the Nature paper write that it’s “unfortunate” that the 21st century warming trend has been framed as having “stalled,” “stopped,” “paused” or “entered a ‘hiatus.’ ” While “[j]ust exactly how such changes should be referred to is open to debate,” the authors suggest “reduced rate of warming,” “decadal fluctuation” and “temporary slowdown” as some possibilities.

Both papers diverge when it comes to the specific questions the researchers asked, and, accordingly, how they quantified the slowdown.

The authors of the Science paper compared the rate of warming during the period between 2000 and 2014 with that of 1951 to 1999, though they also investigated trends in warming dating back to 1880.

The Nature authors, alternatively, compared the warming rate of 2001 to 2014 with a shorter period — 1972 to 2001.

The rationale for using different time periods is tied, at least in part, to the ultimate aim of each study.

The Science study was designed to determine if the global warming trend for “the first 15 years of the 21st century is at least as great as the last half of the 20th century.” It found there was no “slowdown” in global warming compared with this 50-year period.

The Nature study, on the other hand, strove to figure out whether the rates of global warming fluctuate every few decades, so the authors compared the first 15 years of the 21st century with a shorter time period. They reported that the rate had slowed down from 1950 to 1972, then sped up from 1972 to 2001, and then slowed again from 2001 to 2014. “A warming slowdown is thus clear in observations; it is also clear that it has been a ‘slowdown,’ not a ‘stop,’ ” the study concluded.

Meehl told us by email that it was mainly the Karl study’s “interpretation of different trend lengths [discussed above] that we took issue with.”

However, Meehl said he did not find the Karl study’s methods to be “controversial.” The adjustments the NOAA scientists made to their data, which Smith has criticized, “were fairly minor,” added Meehl, and involved calibrating different sets of data to each other.

For example, data on sea surface temperatures alone can come from buoys, ship engine-intake systems and buckets dropped off the side of a ship. As the Science study states, “ship data are systematically warmer than the buoy data,” so adjustments need to be made to calibrate them to each other.

The same inconsistencies occur when data are collected from different land stations. In fact, the Nature paper describes the Karl study’s identification and correction of these data “errors and inhomogeneities” as “of high scientific value.”

Michael Mann, a climate scientist at Penn State University and an author on the Nature paper, wrote Smith an open letter on March 3, which directly addressed the chairman’s false claims.

In his letter, which was posted on Facebook, Mann wrote: “Please don’t misrepresent our recent Nature Climate Change commentary. Our study does NOT support the notion of a ‘pause’ in global warming, only a *temporary slowdown*, which was due to natural factors, and has now ended.”

In sum, based on their different questions and correspondingly different time period comparisons, the Science and Nature studies came to different, though equally valid, conclusions about the warming rate in the early 21st century. Regardless, neither paper supported a halt in global warming, as Smith claimed.

Editor’s Note: SciCheck is made possible by a grant from the Stanton Foundation.